Crown cap



Sept. 28, 1965 M. SPECTOR 3,208,618

CROWN CAP Filed. Dec. 9, 1963 INVENTOR.

United States Patent 3,208,618 CROWN CAP Morris Specter, Highland Park,Ill., assignor to National Can Corporation, Chicago, Ill., a corporationof Delaware Filed Dec. 9, "1963, Ser. No. 328,870 2 Claims. (Cl. 215-46)This invention relates to improvements in crown caps, particularly acrown cap that may be removed from the container upon which it ismounted without the use of a tool opener.

The crown cap is of the type stated in which the cap has a plurality ofupwardly extending tabs circumferentially spaced around the skirt of thecap and which may be grasped to tear the cap and facilitate its removalfrom the container. It is an object of the present invention to providea cap of the type stated with a plurality of score lines on the insideof the crown to facilitate bending of the crown after tearing of thetabs, thereby facilitating removal of the cap from the container. Byhaving the score lines on the inside of the crown, the score lines donot interfere with lithographing the caps nor do the score lines tend tomar the appearance of the finished cap.

It is a further object of the present invention to provide a cap of thetype stated in which the score lines extend from adjacent to but spacedfrom the tops of the tabs so that the score lines do not Weaken the bodyof the cap in the regions between the ends of the score lines and thetops of the tabs.

It is an additional object of the present invention to provide a cap ofthe type stated that does not interfere with or require modification ofhigh speed capping machinery in order to mount the caps onto thecontainers.

The attainment of the above and further objects of the present inventionwill be apparent from the following specification taken in conjunctionwith the accompanying drawing forming a part thereof.

In the drawing:

FIGURE 1 is a top plan view of a crown cap constructed in accordancewith and embodying the present invention;

FIGURE 2 is a vertical sectional view through the central axis of thecap shown mounted in place on the neck of a container;

FIGURE 3 is a side elevational view of the cap shown mounted on thecontainer;

FIGURE 4 is a top plan view of a modified form of crown cap thatembodies the present invention; and

FIGURE 5 is a transverse sectional view, on an enlarged scale, of aportion of the crown and sealing disc therebelow in the region of one ofthe score lines.

Referring now in more detail to the drawing 1 desig nates a crown capthat comprises a metal body 3 of sheet metal, such as aluminum or blackplate having a top or crown 5 and an annular skirt 7 that depends fromthe periphery of the crown 5 and terminates in a rim or free end 9. Thebottom portion 13 of the skirt 7 is outwardly directed and generallyconical while the upper portion 15 of the skirt 7 is generallycylindrical. The skirt 7 is corrugated by circumferentially spacedflutes 17 that extend from the free end 9 upwardly toward the crown 5.The flutes 17 extend across the lower portion 13 and then upwardly intothe upper or cylindrical portion 15.

Formed in the body 3 are a plurality of inverted U- shaped slits 19 thatdefine identical, upwardly extending, circumferentially spaced tear tabs21, 21, 21. Each slit has a curved bight 23 that defines the top of thetab 21 with the highest point of the bight lying approximately at thecurved juncture of the skirt and the crown, and preferably below thecrown. The sides 25, 27 of each slit, which define the sides of the tabs21, terminate at spaced points above the free end 9 of the skirt 7,thereby to leave regions 29, 31 of soild metal between the terminals ofthe slits and the free end 9 of the skirt. Preferably also the sides 25,27 of each slit lie along the ridges of two adjacent flutes 17. Thethree tabs may be equally spaced around the periphery of the skirt 7.

Formed on the underside of the crown 5 are three straight score lines33, 33, 33. The score lines 33 extend between the tabs 21, 21, 21 butthe respective terminals 35 of the score lines 33 stop a substantialdistance short of the bights 23 of the slits, thereby to leave gaps 39of unscored metal between the terminals 35 of the score lines and thetabs 21. This provides a continuous unweakened joint between the crownand the skirt in the region between the tops of the tabs and theterminals of the score lines. One of the score lines 33 is shownexaggerated in FIGURE 5 for purposes of illustration only. Actually, themaximum distance between the sides 34, 34 of the score line 33 is closeto zero.

The cap 1 has a conventional flexible gas impervious yielding sealingliner 41 underlying the crown 5 and is of a diameter of approximatelythat of the internal diameter of the skirt at the crown. The liner 41may be of cork with an impermeable plastic disc adhesively secured tothe underside thereof. The liner is held onto the cap in any standardmanner.

The cap 1 may be mounted on the container 11 by conventional high speedcapping machinery. During the capping operation, the skirt 7 is radiallyoutwardly flexed to snap over the container bead 43 and then moves underits natural resiliency, or is mechanically moved, radially inwardly intogripping engagement with the underside of the container bead 43 to holdthe cap onto the container bead by the hoop strength of the distendedskirt. The portions 45 of the skirt between the flutes engage the bottlebead as shown in FIGURES 2 and 3. The gripping of the container bead bythe skirt also presses the sealing liner 41 downwardly into firm sealingengagement with the top of the container bead 43. The continuous regions39, 39 on opposite sides of each tab help to press the liner 41downwardly at each tab.

When it is desired to remove the cap 1, the tear tabs 21 are grasped byinserting the fingernail behind the tab. The tab is then pulledoutwardly and then downwardly, as shown in dotted lines in FIGURE 2.This tears one or more of the regions 29, 31 of metal adjacent to eachof the respective tabs 21 and thereby breaks the hoop strength of theskirt. The cap may then be removed from the container bead, and tofacilitate such removal, the body 3 may be bent upwardly around one ormore of the score lines 33.

It is customary to lithograph the metal used to form the caps so thatthe exposed surface of the crown is decorated with the name, trademark,or other design. By having the score lines 33 on the underside of thecrown, such score lines do not interfere with the lithography nor dothey tend to mar the decorative appearance of the crown of the cap.

It is also possible to provide a modified form of cap that is shown inFIGURE 4. The cap of FIGURE 4 is similar to the cap previously describedexcept that only two score lines on the underside of the crown 33, 33are used. Furthermore, the three tabs 21a, 21b, 21c, which are allidentical to the tabs 21, are spaced apart such that the are between thetabs 21a and 21b is less than 180 degrees, the arc between the tabs 21band 21c is less than 180 degrees, but the are between the tabs 21a and210 and passing through the tab 21b is greater than 180 degrees. Thethree tabs 21a, 21b and 210 may, of course, be equally spaced just as inthe case of the cap of FIGURE 1, or preferably are unequally spaced, thedistance between the tabs 21a, 21b and 21b, 21c being each slightly morethan 90 degrees and the distance between 210, 21a being greater, butless than 180 degrees.

Except for the tabs and the score lines the crown cap is otherwise ofconventional construction as shown for example in Ramsay Patent1,899,210, Atwood Patent 2,156,258, and Shannon Patent 2,433,629, thedisclosures of which are incorporated herein by reference. Furthermore,the tabs 21, 21, 21 may, if desired, be constructed in the manner shownby the aforesaid Ramsay patent.

In copliance with the requirements of the paten statutes I have hereinshown and described a preferred embodiment of the invention. It is,however, to be understood that the invention is not limited to theprecise construction herein shown, the same being merely illustrative ofthe principles of the inevntion. What is new and is desired to besecured by Letters Patent is:

1. A crown cap comprising a body having a crown and peripheral skirtsurrounding and projecting away from the crown, a sealing liner adjacentto the crown and surrounded by the skirt, said skirt including a curvedportion that is joined to the crown, said skirt being corrugated bycircumferentially spaced flutes formed in and extending from the freeend of the skirt toward the crown with the skirt forming a continuoushoop so that the skirt may be radially inwardly distended throughout itsentire extent into gripping engagement with a bead on a container neckto hold the cap in place on the container neck by the hoop strength ofthe distended skirt, first, second and third circumferentially spacedtear tabs on the body to facilitate removal of the cap from thecontainer neck, said tabs each projecting toward the crown and eachbeing defined by a generally U-shaped slit in the body with the bight ofthe U defining the end of the tab and with said bight beingsubstantially entirely in the skirt, the portions of the slit definingthe sides thereof terminating at spaced points adjacent to but spacedfrom said free end of the skirt so that any tab may be pulled to tearthe part of the skirt between the ends of the slit and said free end,the are between the first and second tabs being less than 180 degreesand the are between the first and third tabs and which passes throughthe second tab being greater than 180 degrees, said crown having atleast two chord-like score lines that are radially outwardly of thecenter of the crown and of a depth less than that of the material of thecrown and along any of which the body may be bent after tearing of twoof the tabs, each score line lying between two of the tabs andterminating at its opposite ends in the crown adjacent to but spacedfrom each of said two tabs, the crown being its normal thickness at itsperipheral portion to provide a continuous annular unweakened region atthe periphery of the crown to assist in pressing the liner against acontainer neck at said continuous region.

2. A crown cap according to claim 1 in which the score lines are on theinside .of said crown.

References Cited by the Examiner UNITED STATES PATENTS 1,899,210 2/33Ramsay 215-46 2,156,258 5/39 Atwood 2l5-46 2,433,629 12/47 Shannon -46FOREIGN PATENTS 896,107 5/62 Great Britain.

FRANKLIN T. GARRETT, Primary Examiner.

GEORGE O. RALSTON, Examiner.

1. A CROWN CAP COMPRISING A BODY HAVING A CROWN AND PERIPHERAL SKIRTSURROUNDING AND PROJECTING AWAY FROM THE CROWN, A SEALING LINER ADJACENTTO THE CROWN AND SURROUNDED BY THE SKIRT, SAID SKIRT INCLUDING A CURVEDPORTION THAT IS JOINED TO THE CROWN, SAID SKIRT BEING CORRUGATED BYCIRCUMFERENTIALLY SPACED FLUTES FORMED IN AND EXTENDING FROM THE FREEEND OF THE SKIRT TOWARD THE CROWN WITH THE SKIRT FORMING A CONTINUOUSHOOP SO THAT THE SKIRT MAY BE RADIALLY INWARDLY DISTENTED THROUGHOUT ITSENTIRE EXTENT INTO GRIPPING ENGAGEMENT WITH A BEAD ON A CONTAINER NECKTO HOLD THE CAP IN PLACE ON THE CONTAINER NECK BY THE HOOP STRENGTH OFTHE DISTENDED SKIRT, FIRST, SECOND AND THIRD CIRCUMFERENTIALLY SPACEDTEAR TABS ON THE BODY TO FACILITATES REMOVAL OF THE CAP FROM THECONTAINER NECK, SAID TABS EACH PROJECTING TOWARD THE CROWN AND EACHBEING DEFINED BY A GENERALLY U-SHAPED SLIT IN THE BODY WITH THE BIGHTBEING OF U DEFINING THE END OF THE TAB AND WITH SAID BIGHT BEINGSUBSTANTIALLY ENTIRELY IN THE SKIRT, THE PORTIONS OF THE SLIT DEFININGTHE SIDES THEREOF TERMINATING AT SPACED POINTS ADJACENT TO BUT SPACEDFROM SAID FREE END OF THE SKIRT SO THAT ANY TAB MAY BE PULLED TO TEARTHE PART OF THE SKIRT BETWEEN THE ENDS OF THE SLIT AND SAID FREE END,THE ARC BETWEEN THE FIRST AND SECOND TABS BEING LESS THAN 180 DEGREESAND THE ARC BETWEEN THE FIRST AND THIRD TABS AND WHICH PASSES THROUGHTHE SECOND TAB BEING GREATER THAN 180 DEGREES, SAID CROWN HAVING ATLEAST TWO CHORD-LIKE SCORE LINES THAT ARE RADIALLY OUTWARDLY OF THECENTER OF THE CROWN AND OF A DEPTH LESS THAN THAT OF THE MATERIAL OF THECROWN AND ALONG ANY OF WHICH THE BODY MAY BE BENT AFTER TEARING OF TWOOF THE TABS, EACH SCORE LINE LYING BETWEEN TWO OF THE TABS ANDTERMINATING AT ITS OPPOSITE ENDS IN THE CROWN ADJACENT TO BUT SPACEDFROM EACH OF SAID TWO TABS, THE CROWN BEING ITS NORMAL THICKNESS AT ITSPERIPHERAL PORTION TO PROVIDE A CONTINUOUS ANNULAR UNWEAKENED REGION ATTHE PERIPHERY OF THE CROWN TO ASSIST IN PRESSING THE LINER AGAINST ACONTAINER NECK AT SAID CINTINUOUS REGION.